The code sample below will show you how to create a GL Account in eConnect.
The code sample requires the eConnectHelper class, which can be found on the eConnect Index page
Here we use the GLAccountType and otaUpdateCreateAccountRcd nodes
The documentation for this schema says that it will uset update whatever you send and that no parameters are required... but as far as I can tell, that's not true. You have to supply about 7 paramaters or it will error with a very odd error. See this post for details: http://dyndeveloper.com/thread.aspx?Threadid=834